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Passivity-Based Stabilization for Switched Stochastic Nonlinear Systems

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IEEE/CAA Journal of Automatica Sinica 2024年第5期11卷 1307-1309页

作者： yaowei Sun Jun Zhao School of Automation Zhengzhou University of AeronauticsZhengzhou 450046 Henan Key Laboratory of General Aviation Technology Zhengzhou University of AeronauticsZhengzhou 450046China College of Information Science and Engineering Northeastern UniversityShenyang 110819China

Dear Editor,This letter addresses the passivity-based mean square exponential stabilization problem for switched stochastic nonlinear systems.A concept of generalized small-time norm-observability is presented and an appropriate test condition is also *** pre-given passivity rate and average dwell time,a set of feedback controllers is designed by use of the passivity property.

关键词： property letter stabilization

Flow-structure interaction of an inverted flag in a water tunnel

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Science China(Physics,Mechanics & Astronomy) 2019年第12期62卷 57-67页

作者： yaowei Hu JiangSheng Wang JinJun Wang Christian Breitsamter Key Laboratory of Fluid Mechanics(Beihang University) Ministry of EducationBeijing 100191China Lehrstuhl fur Aerodynamik und Stromungsmechanik Technische Universitat MiinchenGarching 85748Germany

Herein, the dynamics and flow fields of an inverted flag are studied using hydrogen bubble flow visualization and particle image velocimetry technologies at different height-to-length ratios and flow velocities in a water tunnel. Results show that the heightto-length ratio of the inverted flag at which the critical flow velocity remains nearly constant is approximately 1.4. Moreover, a nonperiodic flapping phenomenon is observed under various height-to-length ratios. This phenomenon may be attributed to the existence of multiple equilibrium solutions to the self-excited vibration system, thus engendering chaos in the system comprising an inverted flag and surrounding fluid. Other indications that the system has entered chaos include multiple frequencies, nonoverlapping phase diagram, and positive Lyapunov exponent. Further discussion of the flow fields around the inverted flag reveals that the large-amplitude oscillation is due to the flow separation, while the flapping instability is a static divergence instability. In the large flapping mode, the starting leading-edge vortex(LEV) is wrapped by Kelvin-Helmholtz instabilities,which are arranged at almost uniform spacing along a circular path. In addition, the variation in position, circulation, and radius of the starting LEV are discussed in detail.

关键词： inverted flag modes aperiodic flapping LEV

A new calibration method for radon detector in seismic systems

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Earthquake Science 2024年第5期37卷 445-458页

作者： Hongwei Ren yaowei Liu Institute of Geophysics China Earthquake AdministrationBeijing 100081China National Institute of Natural Hazards Ministry of Emergency ManagementBeijing 100085China

Radon observation is an important measurement item of seismic precursor network *** radon detector calibration is a key technical link for ensuring radon observation *** present,the radon detector calibration in seismic systems in China is faced with a series of bottleneck problems,such as aging and scrap,acquisition difficulties,high supervision costs,and transportation limitations of radon *** a result,a large number of radon detectors cannot be accurately calibrated regularly,seriously affecting the accuracy and reliability of radon observation data in *** solve this problem,a new calibration method for radon detectors was *** advantage of this method is that the dangerous radioactive substance,i.e.,the radon source,can be avoided,but only“standard instruments”and water samples with certain dissolved radon concentrations can be used to realize radon detector *** method avoids the risk of radioactive leakage and solves the current widespread difficulties and bottleneck of radon detector calibration in seismic systems in *** comparison experiment with the traditional calibration method shows that the error of the calibration coefficient obtained by the new method is less than 5%compared with that by the traditional method,which meets the requirements of seismic observation systems,confirming the reliability of the new *** new method can completely replace the traditional calibration method of using a radon source in seismic systems.

关键词： radon detector calibration “standard instrument” scintillation chamber radon source

Efficient hydrogenation of furfural to furfuryl alcohol by magnetically recoverable RuCo bimetallic catalyst

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Green Energy & Environment 2022年第2期7卷 275-287页

作者： Yongxing Wang Tianyu Gao yaowei Lu Yinghao Wang Qiue Cao Wenhao Fang School of Chemical Science and Technology Key Laboratory of Medicinal Chemistry for Natural Resource-Ministry of EducationYunnan UniversityKunming650091China National Demonstration Center for Experimental Chemistry and Chemical Engineering Education Yunnan UniversityKunming650091China

A magnetically recoverable Ru Co bimetallic catalyst was reported for the catalytic hydrogenation of furfural to furfuryl alcohol under ambient H_(2) *** magnetic catalyst was prepared by H_(2) treatment of the Ru Co composite precursor from a facile one-pot hydrolysis of Co and Ru salts by NaBH_(4) *** catalyst can totally convert furfural to 98–100% furfuryl alcohol at 120°C under 1 bar H_(2) in isopropanol or water using only molecular H_(2) as hydrogen ***,the catalyst showed excellent stability during recycling test and can be easily and completely recovered by magnet from reaction *** influence of Ru/Co ratio and H_(2)-treatment temperature was studied,which were shown to be important for the structural evolution and the metal interaction in Ru Co active sites,based on the comprehensive characterizations including XRD,TGA,TEM,XPS,H_(2)-TPR,CO adsorbed *** was demonstrated that the cooperative Ru~0–Co~0 bimetallic active sites in strong interaction can significantly promote activity and selectivity of the catalyst due to an enhanced adsorption and activation of furfural and H_(2),and simultaneously created a strong magnetism in the Ru Co catalyst for simple physical separation.

关键词： solution catalyst alcohol

Passivity-based Stabilization for a Strict-feedback Nonlinear System under a Proper State-dependent Switching 36

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Passivity-based Stabilization for a Strict-feedback Nonlinea...

第36届中国控制会议

作者： yaowei Sun Jun Zhao State Key Laboratory of Synthetical Automation for Process Industries (Northeastern University) College of Information Science and EngineeringNortheastern University College of Mathematics and Statistics Zhoukou Normal University

ISBN: (纸本)9781538629185

In this paper, the passivity-based stabilization problem of a strict-feedback nonlinear system under a proper statedependent switching law is investigated. Here, the feedback passification problem of each subsystem does not need to be solvable. First, by using the recursive backstepping technique, a sufficient condition under which the closed-loop switched system with designed state feedback controllers is strictly passive from the new input to a designed virtual output is given under a state-dependent switching law. Moreover, the asymptotical stability property of the switched system is achieved by redesigning the introduced new input based on passivity. Finally, a numeral example shows the effectiveness of the proposed method.

关键词： Switched nonlinear systems Passivity Recursive backstepping

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软枣猕猴桃脱涩方法的比较

农产品加工 2022年第23期 27-29,34页

作者：彭耀伟李浙浙赵润德张晨张聪聪王春雨王东升程蓓蓓河北科技师范学院园艺科技学院河北秦皇岛066004 河北省特色园艺种质资源挖掘与创新利用重点实验室河北秦皇岛066000

为探究不同脱涩处理对软枣猕猴桃的影响,以软枣猕猴桃为试验材料,以自然成熟的软枣猕猴桃为对照,以1.5%的盐温水、真空和二氧化碳为3个不同的处理组进行脱涩处理,通过测定软枣猕猴桃的硬度,可溶性糖、单宁含量等指标的变化来分析不同脱... 详细信息

为探究不同脱涩处理对软枣猕猴桃的影响,以软枣猕猴桃为试验材料,以自然成熟的软枣猕猴桃为对照,以1.5%的盐温水、真空和二氧化碳为3个不同的处理组进行脱涩处理,通过测定软枣猕猴桃的硬度,可溶性糖、单宁含量等指标的变化来分析不同脱涩方式对软枣猕猴桃脱涩的影响。结果表明,不同的脱涩方式中,二氧化碳和盐水处理24 h后的软枣猕猴桃的单宁质量浓度均低于成熟果实中的单宁质量浓度,再放置5 d后经过真空处理的软枣猕猴桃的可溶性糖质量浓度和自然放熟的相同,都为0.27 mg/mL,略低于成熟的可溶性糖质量浓度,硬度均比成熟和自然放熟的高。通过研究可知,使用真空进行脱涩可以在保持软枣猕猴桃硬度的同时,其单宁、可溶性糖质量浓度与自然放熟的质量浓度几乎相同。研究结果有助于合理选择软枣猕猴桃的脱涩方式,降低生产成本。

关键词：软枣猕猴桃脱涩单宁可溶性糖

Generation of VP5 deficient mutant of infectious bursal disease virus strain HZ2

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Chinese Science Bulletin 2006年第15期51卷 1909-1912页

作者： LI Long WEI Yongwei HUANG yaowei YU Lian Institute of Preventive Veterinary Medicine Zhejiang University Hangzhou 310029 China Department of Biomedical Engineering Zhejiang University Hang zhou 310027 China

Infectious bursal disease virus (IBDV) is a bi-segmented, dsRNA virus of the Birnaviridae family. The nonstructural protein VP5 has been re- ported to be associated with virus-induced cell apoptosis and pathogenicity, but its role in viral rep- lication has not been unequivocally identified. Based on a PCR introduced mutagenesis strategy, the 33 bp of 96―129 bp located between ORF A1and ORF A2 of genomic segment A of IBDV strain HZ2 were de- leted, and an Nhe I (GcTaGc) site was inserted at 96―102 bp simultaneously. The mutated segment A was ligated into pCI, resulting in pCI-ANhe3. A chi- meric and deficient IBDV strain, named strain ANhe3, was recovered from chicken embryo fibroblast (CEF) cells by co-transfection with pCI-ANhe3 and pCI-mB, derived from the genomic segment B strain HZ2. The indirect fluorescent assay identified that strain ANhe3 could replicate on CEF cells without expression of VP5. Further examination showed that the patho- genesis of strain ANhe3 replicating on SPF chicken embryos was attenuated compared to strain HZ2. This paper provides a new rapid rescue strategy for gene-deleted virus. This strategy lays a basis for gene-deleted vaccine of IBDV.

关键词： IBDV VP5 dsRNA 双核糖核酸病毒基因突变

Extracting Integrated Features of Electronic Medical Records Big Data for Mortality and Phenotype Prediction

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Chinese Journal of Electronics 2024年第3期33卷 776-792页

作者： Fei LI Yiqiang CHEN Yang GU yaowei WANG Institute of Computing Technology University of Chinese Academy of Sciences pengcheng Laboratory

The key to synthesizing the features of electronic medical records(EMR) big data and using them for specific medical purposes,such as mortality and phenotype prediction,is to integrate the individual medical event and the overall multivariate time series feature extraction automatically,as well as to alleviate data imbalance *** paper provides a general feature extraction method to reduce manual intervention and automatically process large-scale *** processing uses two variational auto-encoders(VAEs) to automatically extract individual and global *** avoids the well-known posterior collapse problem of Transformer VAE through a uniquely designed "proportional and stabilizing" mechanism and forms a unique means to alleviate the data imbalance *** conducted experiments using ICU-STAY patients' data from the MIMIC-Ⅲ database and compared them with the mainstream EMR time series processing *** results show that the method extracts visible and comprehensive features,alleviates data imbalance problems and improves the accuracy in specific predicting tasks.

关键词： Databases Time series analysis MIMICs Manuals Big Data Feature extraction Transformers

Experimental investigation on the origin of carbonaceous materials in the fault zone of the Wenchuan earthquake

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Earthquake Science 2024年第3期37卷 189-199页

作者： Deyang Shi yaowei Liu Jin Shi Institute of Geophysics China Earthquake AdministrationBeijing 10081China National Institute of Natural Hazards Ministry of Emergency Management of People's Republic of ChinaBeijing 10085China College of Metallurgy and Energy Engineering Kunming University of Science and TechnologyKunming 650093China

Carbonaceous materials in seismic fault zones may considerably influence seismic fault slip;however,the formation mechanism of carbonaceous materials remains *** this study,we proposed a novel hypothesis for the formation of carbonaceous materials in fault ***,we conducted a CO_(2) hydrogenation experiment in a high-temperature reactor at a co-seismic temperature,with fault gouge formed during the Wenchuan earthquake as the *** experimental results demonstrate that carbonaceous materials in fault zones are formed on the fault gouge during the chemical reaction process,suggesting that the carbonaceous materials are possibly generated from the catalytic hydrogenation of CO_(2),followed by thermal cracking of its *** results of this study provide a theoretical basis for understanding fault behavior and earthquake physics.

关键词： carbon dioxide hydrogenation carbonaceous mineral formation co-seismic temperature fault weakening fault gouge